if you see somebody carrying something odd that doesn't fit in the environment, you should seek out law enforcement and bring it to their attention. >> gretchen: you say to look at the people around you. even to the point of no problem staring at them. why? >> yes. as people, we don't like to look at people. anything more than two seconds, you're scary and being rude. you know what? be rude. pay attention to who is next to you. what are they wearing? how do they look? how are they carrying themselves? look at their behaviors. what are they communicating to you not just verbally, but nonverbally. >> gretchen: know where you will evacuate. oftentimes when people get on airplanes, they'll say i'm five rows from the nearest exit. you're talking about just in general, right? >> yes. whether indoors or outdoors. this specific event, you're barricaded in in an area. you're watching the marathon go on. when you get there, assess. if something happens, i want two ways out. if something happens on this side, i will go out this way. if something happens on this side, i will go out that way. always